“He got hit in the hip, very similar to having a hip pointer in football. It’s affecting him. I was concerned he was grabbing something else,” Rivers said. “In a couple timeouts, I was asking if he was OK.”

But Garnett wasn’t so lucky with the referees: He picked up two quick fouls early in the first quarter and was in foul trouble the whole game. Garnett played only 24 minutes in Tuesday night’s 87-71 loss in Game 2 – the third-fewest of his playoff career – and finished with 12 points with 11 rebounds.

“Him getting in foul trouble had a huge impact on the game. It hurt us, it was clear,” Rivers said. “He really never was allowed to get his rhythm again.”

He added: “Listen, if Carmelo (Anthony) gets in foul trouble, it’s going to have a huge impact on the game for them. It did for us, no doubt.”

Garnett said he would have to do better.

“Fouls are part of the game,” he said Tuesday night. “I have to position myself not to foul so much.”

Carmelo Anthony scored 34 points and J.R. Smith added 19 to help New York take a 2-0 lead over the Celtics in the best-of-seven series. Raymond Felton added 16 points as the Knicks moved halfway to their first series victory since 2000.

Paul Pierce scored 18 points for the Celtics, who will host Game 3 on Friday in their first home game since the Boston Marathon bombings. The Celtics were outscored 32-11 in the third quarter and put up only 23 points in the second half.

“That’s what playoff basketball is like in the East. Points are hard to come by,” Knicks coach Mike Woodson said. “Last night’s game was great for us because we did break loose in the third quarter.”

The Celtics missed 10 of their first 11 shots of the third while getting outscored 24-4 to open the period. In Game 1, an 85-78 loss, Boston scored just eight points in the fourth and 25 in the second half.

Asked if he was working on his halftime speech, Rivers said, “If it’s going to come to that, we’re in trouble.”

“But we have to do something, you’re darn right about that,” he said. “Because we’ve come out flat back-to-back halftimes. I don’t know what that is. As a coach that’s an alarm. I don’t know what it is, but we have to figure out what it is.”

The Celtics vowed to get Garnett more involved after he shot 4 of 12 while scoring eight points in the opener. But that plan was quickly wrecked when he picked up two fouls in the first 3:20 of Game 2.

Afterward, Rivers said the fouls were “horrendous,” but he backtracked Wednesday.

“All I basically said was, Kevin getting into foul trouble had a huge impact on the game,” Rivers said. “That’s not criticizing officials. So I’ve just got to make sure I focus on our stuff.”